The proposed research concerns the development of new procedures for long-term cryogenic storage of human bone-marrow cells and white blood cells suitable for clinical use. We will investigate lysosomal stabilizing agents and inhibitors of lysosomal enzymes including gold salts which have been shown by the author to increase the effectiveness of cryopreservation procedures. The mechanism of action of gold salts will be studied to guide the further selection and studies of compounds of possible use. The determination of cell viability will be done by methods including manual and automated determinations of fluorescence generated within bone marrow and white blood cells from fluoresecein diacetate hydrolyzed to fluorescein within living cells. Live and dead cells will be counted with a Cytofluorograf. The determination of the phagocytic and bacteriocidal activities of white blood cells will also be done with methods adapted for automation with this apparatus.